1. Field
The present invention relates to an exhaust device for an engine which has a muffler connected to an exhaust pipe having a curved portion or a bent portion.
2. Description of the Related Art
Exhaust devices for engines in which the downstream portion of an exhaust pipe connected to a muffler is curved are already known from documents such Patent Document 1, Japanese Patent Laid-Open No. 2001-227336.
If the curved or bent downstream portion of the exhaust pipe develops a pressure distribution such that the pressure of the exhaust gas in the muffler changes circumferentially, then the pressure of the exhaust gas in the muffler tends to become unbalanced, failing to sufficiently deliver the engine output.
As disclosed in Patent Document 1, in a muffler having an annular chamber defined between inner and outer pipes and filled with an acoustic absorbent such as glass wool or the like, the unbalanced pressure of the exhaust gas in the inner pipe may possibly cause an unbalanced deterioration of the acoustic absorbent, tending to shorten the interval for replacing the acoustic absorbent.